1. Field of the Invention
The present invention relates to novel N-benzoyl-N'-(3-nitrophenyl) urea compounds, antitumorous compositions containing them as active ingredients, a method for therapy of cancer by using these compounds, and a process for producing these compounds. More particularly, the present invention relates to the novel compounds including N-benzoyl-N'-(4-pyridyloxy-3-nitrophenyl) urea compounds, N-benzoyl-N'-(4-pyrimidinyloxy-3-nitrophenyl) urea compounds and N-benzoyl-N'-(4-pyridazinyloxy-3-nitrophenyl) urea compounds.
2. Discussion of the Background
Compounds similar to the compounds of the present invention are disclosed in the following publications. Namely, N-benzoyl-N'-pyridyloxyphenyl urea compounds are disclosed in (1) U.S. Pat. No. 4,310,530, (2) Japanese Unexamined Patent Publication No. 99569/1982, and (3) Japanese Unexamined Patent Publication No. 109721/1982, and N-benzoyl-N'-pyrimidinyloxyphenyl urea compounds are disclosed in (3) Japanese Unexamined Patent Publication No. 109721/1982. Further, N-benzoyl-N'-pyridazinyloxyphenyl urea compounds are disclosed in (4) Japanese Unexamined Patent Publication No. 15272/1981.
In the above publications (1), (2) and (4), it is disclosed that these compounds are useful as pesticides, particularly as insecticides. However, the above publications contain no indication that the compounds of the present invention have high antitumour activities. In the publication (3), it is disclosed that these compounds are useful as antitumour drugs. However, there is no description that the compounds of the present invention have much higher antitumour activities.